diff --git a/CMakeLists.txt b/CMakeLists.txt
index 79220b5..7dd6309 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,7 +1,12 @@
-PROJECT(miniz)
+PROJECT(miniz C)
 cmake_minimum_required(VERSION 2.8)
-set(CMAKE_BUILD_TYPE Release)
-set(CMAKE_CONFIGURATION_TYPES Release Debug)
+if(CMAKE_BUILD_TYPE STREQUAL "")
+  # CMake defaults to leaving CMAKE_BUILD_TYPE empty. This screws up
+  # differentiation between debug and release builds.
+  set(CMAKE_BUILD_TYPE "Release" CACHE STRING
+    "Choose the type of build, options are: None (CMAKE_CXX_FLAGS or \
+CMAKE_C_FLAGS used) Debug Release RelWithDebInfo MinSizeRel." FORCE)
+endif ()
 
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_SOURCE_DIR}/bin)